In the top right hand corner, right above the grey bar, it should say "Welcome, (your username)". Click on your username, and it will bring you to a page that shows your latest activity. Under your avatar picture and name there is a link that says, "Find Latest Started Threads" that will bring you to the threads you started.
Hope that helps.
Edit: guess I'm late to the party! When I started typing there were no replies. Guess that goes to show how helpful this place is!